I'm not quite sure on the technology behind a physics card. It's suppose to be a graphics card, but some doesn't have any ports on the back to support a monitor. That's why I'm thinking that you'll need a regular video card in there somewhere.

yeah, hascet explained it pretty well. You always need a vid card, and then the physics card is optional. It calculates stuff (maybe physics? ) so it takes care of some work that would otherwise end up for the gpu. More time for the gpu to do it's own job -> higher fps. (unless something else than the gpu is limiting the fps)

I'm pretty sure it's just like an independent CPU that works solely on the variables in the game to take some of the load off the CPU and RAM. Kinda like how the new Killer NIC has a processor on it to handle all the networking by itself, so your CPU and RAM don't have to work on that. I don't think you need either one of those, really. If you have a decent machine you're fine. It's a pretty niche product at the moment because only a few games actually make use of it.

I wish all games could take advantage of the physics card. I'm just getting into this kind of stuff. Are the Ageia the only company that makes physics card? I'm looking off of Newegg and looks like there aren't a whole lot of selection to choose from.